BS EN 61643-351:2017
$142.49
Components for low-voltage surge protective devices – Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)
| Published By | Publication Date | Number of Pages |
| BSI | 2017 | 32 |
IEC 61643-351:2016 defines test circuits and test methods for determining and verifying the SIT surge parameters. Preferred performance values for key parameters are given. Surge isolation transformers (SITs) are used for signal transformer applications with signal levels up to 400 V peak to peak. SITs are transformers, with or without an internal-winding screen, with a rated impulse withstand voltage greater than the peak voltage of the expected common-mode surge environment. SITs are applicable to components for surge protection against indirect and direct effects of lightning or other transient overvoltage. SITs are used to mitigate the onward propagation of common-mode voltage surges. This part of IEC 61643 does not cover SIT operation under differential-mode lightning surge conditions. Keywords: Surge isolation transformers (SITs)
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | English CONTENTS |
| 8 | FOREWORD |
| 10 | INTRODUCTION |
| 11 | 1 Scope 2 Normative references 3 Terms, definitions, symbols, abbreviations and acronyms 3.1 Terms and definitions |
| 14 | 3.2 Symbols Figures Figure 1 – Symbol for two-winding SIT |
| 15 | Figure 2 – Symbol for a two-winding SIT with polarity indication Figure 3 – Symbol for a two-winding SIT with electric screen Figure 4 – SIT with centre tapped windings |
| 16 | 3.3 Abbreviations and acronyms 4 Service conditions 4.1 Temperature range 4.2 Humidity 4.3 Altitude 4.4 Microclimate Tables Table 1 – Classification of microclimate condition |
| 17 | 5 SIT surge conditions 5.1 SIT surge mitigation Figure 5 – Common-mode surge conditions for SIT |
| 18 | 5.2 Common-mode surges 5.3 Differential-mode surges Figure 6 – Common-mode surge conditions for SIT with an electric screen |
| 19 | 6 Characteristics 6.1 Characteristic measurement 6.2 Input winding to output winding capacitance Figure 7 – Test circuit to measure SIT internal-winding capacitance |
| 20 | 6.3 Insulation resistance (IR) Figure 8 – Test circuit to measure the internal-winding capacitance of SIT with an electric screen |
| 21 | Figure 9 – Test circuit to measure the insulation resistance of SIT Figure 10 – Test circuit to measure the insulation resistance of SIT with an electric screen |
| 22 | 6.4 Signal SIT voltage-time product Figure 11 – Test circuit to measure SIT voltage-time product Figure 12 – Generator and SIT secondary voltage waveforms |
| 23 | 7 Ratings 7.1 Rated impulse withstand voltage Figure 13 – SIT rated impulse voltage test circuit |
| 24 | Figure 14 – Rated impulse voltage test circuit for SIT with an electric screen Figure 15 – Construction of pass/fail template from the 1,2/50 open-circuit waveform |
| 25 | Figure 16 – Pass/fail template and test waveforms |
| 26 | 7.2 Signal SIT rated winding direct current Table 2 – Impulse withstand test voltage for rated impulse voltage |
| 27 | Figure 17 – Winding conductor temperature rise test circuit |
| 28 | 8 Identification 8.1 General 8.2 Datasheet 8.3 Marking |
| 29 | Annex A (informative) 1,2/50 impulse Figure A.1 – 1,2/50 time periods and voltage amplitudes Table A.1 – 1,2/50 voltage impulse generator parameters |
| 30 | Bibliography |
